Ch. XXI.] DEPARTURE FOR ENGLAND. 385 



but that both sexes should not have inherited the change 

 in form and colour when it "would have been beneficial to 

 both can only be explained, I think, on the supposition 

 that the females had a choice of mates and preferred 

 those that retained the primordial appearance of the 

 group. This view is supported by the fact that many of the 

 males of the mimetic Leptalides have the upper half of the 

 lower wing of a pure white, whilst all the rest of the wings 

 is barred and spotted with black, red, and yellow, like 

 the species they mimic. The females have not this white 

 patch, and the males usually conceal it by covering it 

 with the upper wing, so that I cannot imagine its being 

 of any other use to them than as an attraction in court- 

 ship, when they exhibit it to the females, and thus 

 gratify their deep-seated preference for the normal 

 colour of the order to which the Leptalides belong. 



I finally left the mines September 6th, 1872, on my 

 way to England. I was accompanied through the forest 

 by several of the mining officials. Though glad to return 

 to Europe, it was not without some feeling of regret that 

 I rode for the last time through the forest where I had 

 so often wandered during the years I had been at Santo 

 Domingo. The woods had become as familiar to me as 



o 



home scenes. J^o more should I see the white-headed 

 ruby humming-bird come darting down the brook, chasing 

 away the green-throat from its bathing-place. No more 



watch the flocks of many-coloured birds hunting the in- 



it 



sects in the forests, or admire the wonderful instincts of 

 the tropical ants. I listened with pleasure to the last 

 hoarse cries of the mot-mots, and tried to impress on my 



memory the curious forms of vegetation the palm?, the 



c c 



